Cable tension is often the problem shifting onto the bigger chainrings. When you pull the cable taut - will it jump to a bigger ring? If they're STI shifters (brifters) you have to shift "beyond the click." I hate STI's. *grumble* Have a different bike shop check the cable tension. Just my two cents.
"Things look different from the seat of a bike carrying a sleeping bag with a cold beer tucked inside." ~Jim Malusa
2009 Trek 520-Brooks B-17 Special in Antique Brown
2010 Surly Long Haul Trucker-Brooks B-17 Standard in Black
1983 Fuji Espree Single Speed-Brooks B17 British Racing Green